Viscosity index improver--dispersant additive useful in oil compositions

ABSTRACT

Hydrocarbon polymers such as ethylene copolymers may be reacted with unsaturated nitrogen-containing monomers or unsaturated carboxylic acids in the presence of a free radical catalyst such as a peroxide or azo free radical initiator and a chain stopping agent, e.g. a mercaptan to inhibit excessive cross-linking and branching. The copolymer grafted directly with the nitrogen-containing monomers may be utilized as an additive for oil and fuel compositions, particularly lubricating oil compositions as a V.I.-dispersant additive. The polymer reacted with carboxylic acid may be further reacted with amines, polyols, amino-alcohols, etc. to also form a V.I.-dispersant additive.

BACKGROUND OF THE INVENTION

This is a continuation of application Ser. No. 748,031, filed 6-24-85,which is now abandoned, which is a continuation-in-part of our priorapplication Ser. No. 628,345, filed July 6, 1984, now abandoned.

FIELD OF THE INVENTION

The invention relates to polymeric viscosity index (V.I.)improvers--dispersant additives for synthetic and petroleum oils,particularly lubricating oils, These additives comprise a hydrocarbonpolymer, for example a copolymer of ethylene with one or more C₃ to C₂₈alpha-olefins, preferably propylene, or a hydrogenated copolymer ofstyrene and butadiene or isoprene, etc. which have been grafted eitherwith nitrogen-containing monomers such as vinyl pyridine, vinylpyrrolidone, aminomethacrylate, etc. or which have been grafted with anacid moiety, e.g. maleic anhydride, preferably followed by reaction withan amine which will usually be a polyamine. The invention relates toprocesses for preparing the preceding products and the use of theproducts of these processes in oil, particularly lubricating and fuelcompositions. The processes include the direct reaction of either thenitrogen-containing monomer or the unsaturated acid compound with thehydrocarbon polymer per se, preferably in the solid state; that is, inthe absence of solvent or diluent, wherein the grafting is carried outusing a free radical generator, e.g. a peroxide or azo initiator,together with a chain stopping agent, e.g. such as a mercaptan orhydroxyl amine in order to hinder cross-linking and occurrence of oilinsolubility.

PRIOR DISCLOSURES

Ethylene copolymers, particularly ethylene-propylene copolymers, are inwidespread use as viscosity index (V.I.) improving additives for oilcompositions, particularly lubricating oil compositions. A substantialbody of prior art exists directed towards further reacting theseethylene V.I. improvers to form a multi-functional V.I. improver. Thisis a material useful as a V.I.-dispersant oil additive so as to improvenot only the V.I. properties of the oil but to also impart dispersancyso as to suspend sludge that may form during the operation or use of thelubricant and to inhibit varnish deposition in engines. Various patentsteach grafting ethylene copolymers with maleic anhydride, followed byreaction with an amine, either in an oil as a solvent or in a syntheticsolvent such as dichlorobenzene, such as the processes disclosed in U.S.Pat. Nos. 4,137,185, 4,144,181 and 4,089,794. Similarly, prior patents,such as U.S. Pat. Nos. 4,092,255, 4,146,489 and 4,170,561, were directedtowards grafting the ethylene copolymer directly with a nitrogencompound such as vinyl pyridines and vinyl pyrrolidones, usually in achemical solvent such as dichlorobenzene or in an oil as a solvent.

The use of solvents for carrying out these reactions involves theexpense of subsequently removing the solvent and redissolving theadditive in oil to form an oil concentrate, which is the usual way thatsuch additives are marketed. In addition, many of such solvents, such aschlorinated hydrocarbons which do not chain transfer, are expensive andtoxic. The idea of carrying out the reaction directly in an oileliminated the necessity of removing the solvent and gave an economicbenefit. However, subsequent problems have arisen using the oiltechnique since the grafting reaction results in not only the ethylenecopolymer being grafted but also various compounds of the oil reactingto form unwanted materials. These unwanted grafted oil materials are notonly ineffective as V.I. improvers or as dispersants, but in many casesmay cause haze due to the formation of insoluble materials, and aredetrimental to engine performance. In addition, the reaction with theoil molecules uses up valuable reactants.

A third approach was to carry out the formation of the desiredV.I.-dispersant additive in the absence of any substantial amount ofsolvent, either oil or synthetic solvent, at least in carrying out thegrafting reaction. This approach has been suggested by various prior artpatents, such as U.S. Pat. Nos. 4,068,056; 4,068,057 and 4,068,058,wherein amines are directly grafted upon an ethylene-propylene copolymerby mastication or by an extruder, either under a nitrogen atmosphere asin U.S. Pat. No. 4,068,057 or in the presence of oxygen as in U.S. Pat.Nos. 4,068,058 and 4,068,056.

U.S. Pat. No. 3,862,265 has a broad disclosure of extruder-grafting awide range of polymers including ethylene-propylene elastomers withvarious monomers, including maleic anhydride. U.K. Pat. No. 857,797teaches grafting polymers by mastication using peroxide and in thepresence of oxygen or air. U.K. Pat. No. 1,119,629 grafts maleicanhydride onto synthetic rubber in an extruder using inhibitors tocontrol cross-linking. U.K. Pat. No. 832,193 has an extensive disclosurewherein various monomers were grafted by mastication upon variouspolymers using various techniques. The use of chain stopping agents orchain transfer agents have been suggested to inhibit crosslinking, as inU.S. Pat. No. 4,160,072; published Japanese Patent Application No. JA53-110453 (Publication No. 55-36274) 1980, and in Japanese PatentPublication No. 46-35370 (1971).

The use of non-ethylene hydrocarbon polymers to form V.I.-dispersantadditives is also known in the art, such as those of U.S. Pat. Nos.3,903,003; 4,077,893 and U.S. Pat. No. 4,141,847.

The present invention is a further improvement in forming useful oilsoluble additives, wherein the grafting is carried out with thehydrocarbon polymer, preferably a polyolefin in the form of a solidrubber in the substantial absence of any chemical solvent or lubricatingoil. This avoids the need to remove the chemical solvent and it avoidsthe grafting of the oil molecules during the course of the reaction. Thepresent invention preferably utilizes free radical generators, such asperoxides, in order to speed up the graft reaction. However, simplygrafting the hydrocarbon polymer, e.g. ethylene copolymer per se eitherin an extruder or a masticator with peroxide has been found to result incross-linking the polymer with the frequent formation of insoluble gel,or insoluble gel-like portions, when it was attempted to later dissolvethe grafted material in oil. On the other hand, attempting to avoid thegelling by restricting the amount of grafting was unsatisfactory since acertain amount of grafting is necessary to incorporate the desiredamount of nitrogen-containing moieties to achieve the desired degree ofdispersancy. Thus, the present invention differs from the above-notedprior art in utilizing both a free radical generator and a chainstopping agent in carrying out the grafting of a hydrocarbon polymer inthe solid state, i.e. in the substantial absence of solvent or diluent,with an unsaturated monomer which may either be a nitrogen monomer or anunsaturated acid which can then be subsequently reacted with an amine oralcohol, e.g. a polyol, or amino alcohol, in a subsequent reaction toform oil soluble additives.

DESCRIPTION OF PREFERRED EMBODIMENT

Hydrocarbon Polymer

Oil soluble hydrocarbon polymers or copolymers used in the inventiongenerally will have a number average molecular weight (M_(n)) of fromabout 5000 to about 500,000; preferably 10,000 to 200,000 and optimallyfrom about 20,000 to 100,000. In general, polymers useful as V.I.improvers will be used. These V.I. improvers will generally have anarrow range of molecular weight, as determined by the ratio of weightaverage molecular weight (M_(w)) to number average molecular weight(M_(n)). Polymers having a (M_(w) /M_(n)) of less than 10, preferablyless than 7, and more preferably 4 or less are most desirable. As usedherein (M_(n)) and (M_(w)) are measured by the well known techniques ofvapor phase osmometry (VPO), membrane osmometry and gel permeationchromotography. In general, polymers having a narrow range of molecularweight may be obtained by a choice of synthesis conditions such aschoice of catalyst, or principal catalyst and cocatalyst combination,addition of hydrogen during the synthesis, etc. Post synthesis treatmentsuch as extrusion at elevated temperature and under high shear throughsmall orifices, mastication under elevated temperatures, thermaldegradation, fractional precipitation from solution, etc. may also beused to obtain narrow ranges of desired molecular weights and to breakdown higher molecular weight polymer to different molecular weightgrades for V.I. use.

Examples of suitable hydrocarbon polymer include homopolymers andcopolymers of two or more monomers of C₂ to C₂₈, e.g. C₂ to C₁₈ olefins,including both alpha olefins and internal olefins, which may be straightor branched, aliphatic, aromatic, alkylaromatic, cycloaliphatic, etc.Frequently they will be of ethylene with C₃ to C₂₈ olefins, particularlypreferred being the copolymers of ethylene and propylene, and polymersof other olefins such as propylene, butene and polyisobutylene. Alsohomopolymers and copolymers of C₆ and higher alpha olefins can bepreferably employed.

Such hydrocarbon polymers also include olefin polymers such as atacticpolypropylene, hydrogenated polymers and copolymers and terpolymers ofstyrene, e.g. with isoprene and/or butadiene.

The preferred polymers are prepared from ethylene and ethylenicallyunsaturated hydrocarbons including cyclic, alicyclic and acyclic,containing from 3 to 28 carbons, e.g. 2 to 18 carbons. These ethylenecopolymers may contain from 15 to 90 wt. % ethylene, preferably 30 to 80wt. % of ethylene and 10 to 85 wt. %, preferably 20 to 70 wt. % of oneor more C₃ to C₂₈, preferably C₃ to C₁₈, more preferably C₃ to C₈, alphaolefins. While not essential, such copolymers preferably have a degreeof crystallinity of less than 25 wt. %, as determined by X-ray anddifferential scanning calorimetry. Copolymers of ethylene and propyleneare most preferred. Other alpha-olefins suitable in place of propyleneto form the copolymer, or to be used in combination with ethylene andpropylene, to form a terpolymer, tetrapolymer, etc., include 1-butene,1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, etc.; alsobranched chain alpha-olefins, such as 4-methyl-1-pentene,4-methyl-1-hexene, 5-methylpentene-1, 4,4-dimethyl-1-pentene, and6-methylheptene-1, etc., and mixtures thereof.

The term copolymer as used herein, unless otherwise indicated, includesterpolymers, tetrapolymers, etc., preferably of ethylene, said C₃₋₂₈alpha-olefin and/or a non-conjugated diolefin or mixtures of suchdiolefins which may also be used. The amount of the non-conjugateddiolefin will generally range from about 0.5 to 20 mole percent,preferably about 1 to about 7 mole percent, based on the total amount ofethylene and alpha-olefin present.

Representative examples of non-conjugated dienes that may be used as thethird monomer in the terpolymer include:

a. Straight chain acyclic dienes such as: 1,4-hexadiene; 1,5-heptadiene;1,6-octadiene.

b. Branched chain acyclic dienes such as: 5-methyl-1,4-hexadiene;3,7-dimethyl 1,6-octadiene; 3,7-dimethyl 1,7-octadiene; and the mixedisomers of dihydro-myrcene and dihydro-cymene.

c. Single ring alicyclic dienes such as: 1,4-cyclohexadiene;1,5-cyclooctadiene; 1,5-cyclo-dodecadiene; 4-vinylcyclohexene; 1-allyl,4-isopropylidene cyclohexane; 3-allyl-cyclopentene; 4-allyl cyclohexeneand 1-isopropenyl-4-(4-butenyl)cyclohexane.

d. Multi-single ring alicyclic dienes such as: 4,4'-dicyclopentenyl and4,4'-dicyclohexenyl dienes.

e. Multi-ring alicyclic fused and bridged ring dienes such as:tetrahydroindene; methyl tetrahydroindene; dicyclopentadiene; bicyclo(2.2.1) hepta 2,5-diene; alkyl, alkenyl, alkylidene, cycloalkenyl andcycloalkylidene norbornenes such as: ethyl norbornene;5-methylene-6-methyl-2-norbornene; 5-methylene-6,6-dimethyl-2-norbornene; 5-propenyl-2-norbornene;5-(3-cyclopentenyl)-2-norbornene and 5-cyclohexylidene-2-norbornene;norbornadiene; etc.

Other suitable hydrocarbon polymers may be made from styrene, andsubstituted styrenes, such as alkylated styrene, or halogenated styrene.The alkyl group in the alkylated styrene, which may be a substituent onthe aromatic ring or on an alpha carbon atom, may contain from 1 toabout 20 carbons, preferably 1-6 carbon atoms. These styrene typemonomers may be copolymerized with suitable conjugated diene monomersincluding butadiene and alkyl-substituted butadiene, etc., having from 1to about 6 carbons in the alkyl substituent. Thus, in addition tobutadiene, isoprene, piperylene and 2,3-dimethylbutadiene are useful asthe diene monomer. Two or more different styrene type monomers as wellas two or more different conjugated diene monomers may be polymerized toform the interpolymers. Still other useful polymers are derived withoutstyrene and only from aliphatic conjugated dienes, usually having from 4to 6 carbon atoms most usefully, butadiene. Examples are homopolymers of1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-dimethylbutadiene,copolymers formed with at least two of these conjugated dienes andcopolymers of the latter with styrene, these homopolymers and copolymershaving been hydrogenated. These aforesaid polymers with considerableunsaturation are preferably fully hydrogenated to remove substantiallyall of the olefinic unsaturation, although, in some situations, partialhydrogenation of the aromatic-type unsaturation is effected. Theseinterpolymers are prepared by conventional polymerization techniquesinvolving the formation of interpolymers having a controlled type ofsteric arrangement of the polymerized monomers, i.e. random, block,tapered, etc. Hydrogenation of the interpolymer is effected usingconventional hydrogenation processes.

Polyisobutylenes are readily obtained in a known manner as by followingthe procedure of U.S. Pat. No. 2,084,501 wherein the isoolefin, e.g.isobutylene, is polymerized in the presence of a suitable Friedel-Craftscatalyst, e.g. boron fluoride, aluminum chloride, etc., at temperaturessubstantially below 0° C. such as at -40° C. Such isobutylenes can alsobe polymerized with a higher straight chained alpha-olefin of 6 to 20carbon atoms as taught in U.S. Pat. No. 2,534,095 where said copolymercontains from about 75 to about 99% by volume of isobutylene and about 1to about 25% by volume of a higher normal alpha-olefin of 6 to 20 carbonatoms. Copolymers of isobutylene with dienes such as isoprene orpiperylene may also be used.

Ethylenically Unsaturated Carboxylic Acid Material

These materials which are grafted onto the hydrocarbon polymer contain 3to 10 carbon atoms and at least one ethylenic unsaturation and at leastone, preferably two, carboxylic acid groups, or an anhydride group, or apolar group which is convertible into said carboxyl groups by oxidationor hydrolysis. Maleic anhydride or a derivative thereof is preferred asit does not appear to homopolymerize appreciably but attaches onto thepolymer to give two carboxylic acid functionalities. Such preferredmaterials have the generic formula ##STR1## wherein R₁ and R₂ arehydrogen or a halogen. Suitable examples additionally includechloro-maleic anhydride, itaconic anhydride, hemic anhydride or thecorresponding dicarboxylic acids, such as maleic acid or fumaric acid ortheir monoesters, etc.

As taught by U.S. Pat. No. 4,160,739 and U.S. Pat. No. 4,161,452 variousunsaturated comonomers may be grafted on the olefin copolymer togetherwith the unsaturated acid component, e.g. maleic anhydride. Such graftmonomer systems may comprise one or a mixture of comonomers differentfrom the unsaturated acid component and which contain only onecopolymerizable double bond and are copolymerizable with saidunsaturated acid component. Typically, such comonomers do not containfree carboxylic acid groups and are esters containing α,β-ethylenicunsaturation in the acid or alcohol portion; hydrocarbons, bothaliphatic and aromatic, containing α,β-ethylenic unsaturation, such asthe C₄ -C₁₂ alpha olefins, for example isobutylene, hexene, nonene,dodecene, etc.; styrenes, for example styrene, α-methyl styrene,p-methyl styrene, p-sec. butyl styrene, etc.; and vinyl monomers, forexample vinyl acetate, vinyl chloride, vinyl ketones such as methyl andethyl vinyl ketone, etc. Comonomers containing functional groups whichmay cause crosslinking, gelation or other interfering reactions shouldbe avoided, although minor amounts of such comonomers (up to about 10%by weight of the comonomer system) often can be tolerated.

Unsaturated Nitrogen Containing Monomer

Nitrogen containing unsaturated compounds are well known in formingpolymers useful as oil additives. These monomers may be used forgrafting onto the polymer and include, among others those having 6 to 30carbon atoms and 1 to 4 nitrogen atoms.

Nitrogen containing acrylate and methacrylate monomers may be used suchas dimethylaminoethyl methacrylate or acrylate; acrylamides andmethacrylamides such as N-(1,1-dimethyl-3-oxobutyl)acrylamide,N-(1,2-dimethyl-1-ethyl-3-oxobutyl)acrylamide,N-(1,3-diphenyl-1-methyl-3-oxoproyl)acrylamide,N-(1-methyl-1-phenyl-3-oxobutyl)methacrylamide, N,N-diethylaminoethylacrylamide, 2-hydroxyethyl acrylamide, N-dimethylaminopropyl acrylamideand methacrylamide.

N-vinylcaprolactams may be used. These include N-vinylpyrrolidone,N-vinylthiopyrrolidone, 3-methyl-1-vinylpyrrolidone,4-methyl-1-vinylpyrrolidone, 5-methyl-1-vinylpyrrolidone,3-ethyl-1-vinylpyrrolidone, 3-butyl-1-vinylpyrrolidone,3,3-dimethyl-1-vinylpyrrolidone, 4,5-dimethyl-1-vinylpyrrolidone, etc.

Vinyl pyridines may be used, such as 2-vinylpyridine, 4-vinylpyridine,and lower alkyl (C₁ -C₈) substituted C-vinylpyridines, such as2-methyl-5-vinylpyridine, 2-methyl-4-vinylpyridine, 2-vinyl-5-ethylpyridine, 2-vinyl-6-methylpyridine, etc.

Grafting of the Polymer

The grafting of the polymer with the carboxylic acid material ornitrogen monomer may be carried out in an extruder, a rubber mill, aBanbury mixer, Brabender mixers, and other mechanical mixing deviceswhich can mix or knead the rubber at elevated temperatures with theother components of the reaction into a homogeneous solid rubbery massso grafting can take place in the solid state. Combinations of equipmentmay also be used, such as a low temperature mixer for premixing theingredients, following which they can be transferred to a hightemperature heated mixer for grafting.

The radical grafting is preferably carried out using free radicalinitiators such as peroxides, hydroperoxides, and azo compounds andpreferably those which have a boiling point greater than about 100° C.and which decompose thermally within the grafting temperature range toprovide said free radicals. Representative of these free-radicalinitiators are azobutyro-nitrile, di-lauroyl peroxide,2,5-di-methyl-hex-3-yne-2, 5 bis-tertiary-butyl peroxide (sold asLupersol 130) or its hexane analogue, di-tertiary butyl peroxide anddicumyl peroxide. The initiator is generally used at a level of betweenabout 0.005% and about 1%, e.g. 0.05 to 0.5%, based on the total weightof the ethylene copolymer, and temperatures of about 120° to 250° C.

The ethylenically unsaturated nitrogen monomer or carboxylic acidmaterial, preferably maleic anhydride, will be generally used in anamount ranging from about 0.1 to about 10%, preferably 0.5 to 5.0%,based on weight of the initial ethylene copolymer. The aforesaidcarboxylic acid or nitrogen monomer material and free radical initiatorare generally used in a weight percent ratio range of 1.0:1 to 30:1,preferably 4.0:1 to 12:1.

The chain stopping agent is preferably an aliphatic mercaptan having 4to 24 carbon atoms, such as t-butyl mercaptan, n-butyl mercaptan, octylmercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, etc. The tertiarymercaptans and diethyl hydroxyl amine are particularly effective and arethe most preferred. Other chain stopping agents may be used, forexample, cumene, alcohols, phenols, etc. The chain stopper will begenerally used in an amount of 0.05 to 10 wt. %, e.g. 0.1 to 5 wt. %,based on the weight of the ethylene copolymer.

The initiator grafting is preferably carried out at 120°-250° C.,preferably 150°-220° C. An inert atmosphere, such as that obtained bynitrogen blanketing can be used. While the grafting can be carried outin the presence of air, the yield of the desired graft polymer isgenerally thereby decreased as compared to grafting under an inertatmosphere substantially free of oxygen. The total time will usuallyrange from about 0.005 to 12 hours. If carried out in an extruder, thetotal time will be relatively short, e.g. 0.005 to 0.2 hours. In amasticator usually from about 0.5 to 6 hours, more preferably 0.5 to 3hours total time will be required. The graft reaction will be usuallycarried out to at least approximately 4 times, preferably at least about6 times the half-life of the free-radical initiator at the reactiontemperature employed, e.g. with 2,5-dimethyl hex-3-yne-2, 5-bis(t-butylperoxide) 2 hours at 160° C. and one hour at 170° C., etc.

In the grafting process, usually the polymer rubber is first heated toabout 100°-160° C. and below the grafting temperature to facilitatemixing with the other ingredients, such as the unsaturated graftmaterial, e.g. maleic anhydride, chain stopper and initiator, all ofwhich are added with mixing to form a homogeneous mixture. The chainstopper is preferably added before the initiator. The reaction mixturecan then be further heated to grafting temperatures, preferably in therange of about 170° to 240° C. Grafting temperature is the temperaturewhere the initiator breaks down to form free radicals and causesubstantial grafting to take place. When the reaction is complete, theexcess monomer material may be eliminated by an inert gas purge, e.g.nitrogen sparging. Continuous or periodic addition of the graft materialto the reactor can be utilized along with an appropriate portion ofinitiator and chain stopper during the course of the reaction.

In some cases the grafting can take place in several stages by mixingthe reactants together below the grafting temperature; heating to ahigher temperature to graft; cooling below grafting temperature; addingand mixing more unsaturated material, initiator and chain stopper;heating again to the grafting temperature to graft the added material,etc. In still other cases, it may be desirable to heat the polymer tografting temperature and add the chain stopper, the unsaturated acid ornitrogen monomer and the initiator all while at grafting temperatures.Alternatively, the chain stopper can be added to the polymer belowgrafting temperature, and the initiator and unsaturated acid or nitrogenmonomer can be added at grafting temperatures.

After the grafting is complete, diluent oil, such as mineral lubricatingoil, may be mixed into the grafted ethylene copolymer to form aconcentrate. This dilution can be carried out in a masticator used forthe grafting, or dilution can be carried out in a separate heating andmixing vessel. The oil solution can be the final additive product if thegrafting used a N-containing monomer. On the other hand, if unsaturatedacid or anhydride, such as maleic anhydride was grafted on the polymer,then a further reaction with an amine or hydroxy component is carriedout to form a V.I.-dispersant additive. This will usually be carried outusing the diluted grafted polymer, in a separate reaction vessel fromthat used for grafting.

The Amine Component

Useful amine compounds for neutralization of the acid, e.g. maleicanhydride, grafted polymer include mono- and polyamines of about 2 to60, e.g. 3 to 20, total carbon atoms and about 1 to 12, e.g., 2 to 7nitrogen atoms in the molecule. These amines may be hydrocarbyl aminesor may be hydrocarbyl amines including other groups, e.g., hydroxygroups, alkoxy groups, amide groups, imidazoline groups, and the like.Hydroxy amines with 1 to 6 hydroxy groups, preferably 1 to 3 hydroxygroups are particularly useful. Preferred amines are aliphatic saturatedamines, including those of the general formulas: ##STR2## wherein R, R'and R" are independently selected from the group consisting of hydrogen;C₁ to C₂₅ straight or branched chain alkyl radicals; C₁ to C₁₂ alkoxy C₂to C₆ alkylene radicals; C₂ to C₁₂ hydroxy amino alkylene radicals; andC₁ to C₁₂ alkylamino C₂ to C₆ alkylene radicals; s is a number of from 2to 6, preferably 2 to 4; and t is a number of from 0 to 10, preferably 2to 6.

Non-limiting examples of suitable amine compounds include:1,2-diaminoethane; 1,3-diaminopropane; 1,4-diaminobutane;1,6-diaminohexane; polyethylene amines such as diethylene triamine;triethylene tetramine; tetraethylene pentamine; polypropylene aminessuch as 1,2-propylene diamine; di-(1,2-propylene)triamine;di-(1,3-propylene)triamine; N,N-dimethyl-1,3-diaminopropane;N,N-di-(2-aminoethyl)ethylene diamine;N,N-di(2-hydroxyethyl)-1,3-propylene diamine; 3-dodecyloxypropylamine;N-dodecyl-1,3-propane diamine; tris-hydroxymethylaminomethane (THAM);diisopropanol amine; diethanol amine; triethanol amine; mono-, di-, andtri-tallow amines; N-amino alkyl morpholines where the alkyl is 0 to 5carbons such as N-(2-aminoethyl)morpholine; N-(3-aminopropyl)morpholine;substituted pyridines such as 2-amino pyridine; 2-methylamino pyridine;and 3-methylamino pyridine; 2-(2-aminoethyl)pyridine;2-(4-aminoethyl)pyridine; and other amines including 2-amino pyrimidine;2-amino benzothiazole; 2-aminothiazole; 2-amino-2-thiazoline;methyl-1-phenyl hydrazine; isopropyl ethylene diamine; andpara-morpholino aniline; etc.

Other useful amine compounds include: alicyclic diamines such as1,4-di(aminomethyl)cyclohexane, and heterocyclic nitrogen compounds suchas imidazolines, and N-aminoalkyl piperazines of the general formula:##STR3## wherein G is independently selected from the group consistingof hydrogen and omega-aminoalkylene radicals of from 1 to 3 carbonatoms, and p is an integer of from 0 to 4, e.g. 1 to 4. Non-limitingexamples of such amines include 2-pentadecyl imidazoline;N-(2-aminoethyl)piperazine; etc.

Commercial mixtures of amine compounds may advantageously be used. Forexample, one process for preparing alkylene amines involves the reactionof an alkylene dihalide (such as ethylene dichloride or propylenedichloride) with ammonia, which results in a complex mixture of alkyleneamines wherein pairs of nitrogens are joined by alkylene groups, formingsuch compounds as diethylene triamine, triethylenetetramine,tetraethylene pentamine, pentaethylene hexamine, and isomericpiperazines. Low cost poly(ethyleneamines) compounds having acomposition approximating tetraethylene pentamine are availablecommercially under the trade name "Polyamine H" and "Polyamine 400"(PA-400).

Especially preferred are amines having a single primary amine group,with any other amine groups present being tertiary amine groups. Thisminimizes cross-linking and becomes particularly important when thepolymer has a relatively high degree of acidity, e.g. above 0.1 meq./g.of polymer. Mixtures comprising about 70 wt. % or more of amines havingonly a single primary or secondary group may be used with small amountsof amines having two or more primary or secondary amine groups.Acidities below 0.1 meq./g. polymer are less sensitive to cross-linkingand amines with 2 or more reactive groups, i.e. either primary orsecondary amine groups, or both primary and secondary amine groups, or aprimary amine group and an alcohol group, may be used.

The Alcohol Component

The V.I.-ashless dispersants may be esters derived from the aforesaidpolymer grafted with carboxylic acid or anhydride and from hydroxycompounds such as monohydric and polyhydric alcohols or aromaticcompounds such as phenols and naphthols etc. The polyhydric alcohols arethe most preferred hydroxy compound and preferably contain from 2 toabout 10 hydroxy radicals, for example, ethylene glycol, diethyleneglycol, triethylene glycol, tetraethylene glycol, dipropylene glycol,and other alkylene glycols in which the alkylene radical contains from 2to about 8 carbon atoms. Other useful polyhydric alcohols includeglycerol, mono-oleate of glycerol, monostearate of glycerol, monomethylether of glycerol, pentaerythritol, dipentaerythritol, etc.

The ester dispersant may also be derived from unsaturated alcohols suchas allyl alcohol, cinnamyl alcohol, propargyl alcohol,1-cyclohexane-3-ol, and oleyl alcohol. Still other classes of thealcohols capable of yielding the esters of this invention comprise theether-alcohols and amino-alcohols including, for example, theoxy-alkylene, oxy-arylene-, amino-alkylene-, andamino-arylene-substituted alcohols having one or more oxy-alkylene,amino-alkylene, amino-arylene or oxy-arylene radicals. They areexemplified by Cellosolve, Carbitol, N,N,N',N'-tetrahydroxy-trimethylenedi-amine, and the like. For the most part, the ether-alcohols having upto about 150 oxy-alkylene radicals in which the alkylene radicalcontains from 1 to about 8 carbon atoms are preferred.

Especially preferred are monoalcohols when the acidity is above 0.1meq./g. of polymer, while polyols may be used at acidities below 0.1meq./g. of polymer. Preferred V.I.-ester dispersant additives aredi-esters of succinic anhydride moieties formed by grafting ethylenecopolymer with maleic anhydride.

Reaction of Grafted Polymer with Amine or Alcohol Components

The polymer, grafted with acidic moieties, preferably in solutiongenerally equal to about 5 to 30 wt. %, preferably 10 to 20 wt. %polymer, can be readily reacted with amines or alcohols by heating at atemperature of from about 100° C. to 250° C., preferably from 120° to230° C., for from about 0.5 to 10 hours, usually about 1 to about 6hours. The heating is preferably carried out to favor formation ofimides, and amides in the case of amine components, or esters in thecase of alcohol components. Reaction ratios can vary considerably,depending upon the reactants, amounts of excess, type of bonds formed,etc.

Compositions

A minor amount, e.g. 0.001 up to 50 wt. %, preferably 0.005 to 25 wt. %based on the weight of the total composition, of the oil-soluble graftpolymers produced in accordance with this invention can be incorporatedinto a major amount of an oleaginous material, such as a lubricating oilor hydrocarbon fuel, depending upon whether one is forming finishedproducts or additive concentrates. When used in lubricating oilcompositions, e.g., automotive or diesel crankcase lubricating oil, thefinal grafted polymer V.I.-dispersant concentrations are usually withinthe range of about 0.01 to 10 wt. %, e.g., 0.1 to 6.0 wt. %, preferably0.25 to 3.0 wt. %, of the total composition. The lubricating oils towhich the products of this invention can be added include not onlyhydrocarbon oil derived from petroleum, but also include syntheticlubricating oils such as esters of dicarboxylic acids; complex estersmade by esterification of monocarboxylic acids, polyglycols,dicarboxylic acids and alcohols; polyolefin oils, etc.

The V.I.-dispersant graft polymers of the invention may be utilized in aconcentrate form, e.g., from about 5 wt.% up to about 50 wt. %,preferably 7 to 25 wt. %, in oil, e.g., mineral lubricating oil, forease of handling.

The above oil compositions may contain other conventional additives,such as dyes, pour point depressants, antiwear agents, antioxidants,other viscosity-index improvers, dispersants, etc.

The following examples, wherein all parts are parts by weight, whichinclude preferred embodiments, further illustrate the present invention.

EXAMPLE 1

1816 g. of ethylene-propylene solid rubber were added through a hatch inthe top of a 2.5 gal. laboratory masticator, which was then closed, andheated to 140° C. while mixing under a nitrogen stream for about 45minutes. This mixing caused the rubber to band, that is form a stickycohesive mass around the masticator mixer blades. Then, 65 g. of tert.dodecyl mercaptan as chain stopper were added over about 5 minutes,followed by the addition of 62 g. of maleic anhydride over another 5minutes. Next, 7.3 g. of Lupersol 130 dissolved in 7.3 g. ofpolyisobutylene of 500 M_(n) mol. wt. for ease of handling were addedover another 5 minutes. Mixing under nitrogen at 140° C. continuedduring all of said additions.

The temperature was then raised over about 15 minutes to 190° C., wherethe Lupersol rapidly breaks down and the major proportion of thegrafting takes place. The masticator contents were then heat soaked at190° C. for 20 minutes, followed by nitrogen stripping at 1.25 hours at190° C. to remove unreacted maleic anhydride and other volatiles. Then4540 g. of S100NLP (Solvent Neutral lubricating oil of 100 SUS viscosityat 37.8° C., low pour) were added over a period of 1.75 hours at 190° C.The temperature was then dropped to 160° C. for 30 minutes, after whichthe masticator was drained to give the Product of Example 1. All of thepreceding was carried out while mixing under a nitrogen atmosphere. TheProduct of Example 1 was a clear, viscous oil solution of the maleicanhydride grafted rubber. The grafted polymer in this Product analyzed0.149 milliequivalents of acid per g. of polymer, which indicated thatabout 43% of the maleic anhydride charged to the masticator had reacted.

The laboratory masticator used above was a Beken Duplex Mixermanufactured by the Bramley Machinery Corp., Edgewater, N.J. It had a21/2 gal. reactor space heated by a Dow Therm containing outer jacket.The mixing blades were mounted on two oppositely rotating shafts. Oneshaft was rotated at 26 rpm while the other rotated at 52 rpm. Droppingfunnels were used to feed the mercaptan, maleic anhydride, and Lupersol130 solution into the reactor. The reactor was fitted with a nitrogeninlet and an exit vent.

The ethylene-propylene copolymer used above was a V.I. improver forlubricating oil and consisted of about 43 wt. % ethylene and about 57weight % propylene. It had a Thickening Efficiency (T.E.) of about 2.8which represents a number average molecular weight of approximately60,000. It was an amorphous copolymer with a M_(w) /M_(n) of less than4:1.0.

Thickening Efficiency (T.E.) is defined as the ratio of the weightpercent of a polyisobutylene (sold as an oil solution by Exxon ChemicalCo. as Paratone N), having a Staudinger Molecular Weight of 20,000,required to thicken a solvent-extracted neutral mineral lubricating oil,having a viscosity of 150 SUS at 37.8° C., a viscosity index of 105 andan ASTM pour point of 0° F., (Solvent 150 Neutral) to a viscosity of12.4 centistokes at 98.9° C., to the weight percent of a test copolymerrequired to thicken the same oil to the same viscosity at the sametemperature. T.E. is related to (M_(n)) and is a convenient, usefulmeasurement for formulation of lubricating oils of various grades.

EXAMPLE 2

200 g. of the Product of Example 1, that is the oil solution of maleicanhydride grafted ethylene-propylene copolymer were charged to a 2 literlaboratory resin kettle along with 200 g. of S100NLP mineral lubricatingoil. The kettle was equipped with a heating mantle, a dropping funnel,stirrer, overhead water condenser, vacuum pump and a nitrogen inlet formaintaining a nitrogen atmosphere. The temperature was raised to 190° C.while stirring and nitrogen sparging. The temperature was maintained at190° C. For one hour to remove any moisture or volatiles. Then 1.16 g.of 2-aminomethyl pyridine dissolved in 2.38 g. of S100NLP were addedover 10 minutes, followed by continued heating at 190° C. and mixingwhile under nitrogen for one hour. The reaction mixture was thennitrogen stripped for one hour after which the temperature was loweredto 150° C. and 272 g. of S100NLP were added and mixed for 15 minutes,followed by nitrogen sparging for one hour. The reactor was then drainedto give the Product of Example 2 which was an oil solution of theaminated maleic anhydride grafted ethylene-propylene rubber. ThisProduct had a K.V. (Kinematic Viscosity) of 1779 centipoise at 100° C.and was useful as a Viscosity Index improving--sludge dispersantadditive, e.g. for lubricating oils.

The Product of Example 2 was tested for storage stability by storing inan oven at 80° C. At the end of two weeks in the oven, the K.V. at 100°C. was 1768 centipoise. After four weeks in the oven, the K.V. at 100°C. was 1745 centipoise, indicating good thermal storage stability.

EXAMPLE 3

200 grams of the Product of Example 1 were added to the 2 liter resinkettle along with 200 grams of S100NLP. The temperature was raised to190° C. while stirring and nitrogen sparging for a period of one hour.1.16 grams of 2-aminomethyl pyridine dissolved in 2.38 grams of S100NLPwere added over a 10-minute period and reacted for one hour, whilecontinuing the nitrogen sparging. Then the reaction mixture was nitrogenstripped for one hour at 190° C., after which the temperature waslowered to 150° C. and 272 grams of S100NLP were added and mixed for 15minutes, followed by sparging with nitrogen for another hour. Thereaction mixture was then drained to give the product having a K.V. at100° C. of 1779 centistokes.

EXAMPLE 4

The 2 liter resin kettle was charged with 200 grams of the Product ofExample 1 and 200 grams of S100NLP. The temperature was raised to 190°C. while stirring and nitrogen sparging, which conditions weremaintained for one hour, after which 0.90 grams of 2-aminopyrimidinewere added and reacted for one hour under nitrogen. The reaction mixturewas then stripped with nitrogen for one hour at 190° C., after which thetemperature was lowered to 150° C. and 272 grams of S100NLP were addedand mixed for 15 minutes. The reactor was then drained to give theproduct having a K.V. at 100° C. of 1774 centistokes.

EXAMPLE 5

The 2 liter resin kettle was charged with 200 grams of the Product ofExample 1 and 200 grams of S100NLP. The temperature was raised to 190°C. while nitrogen sparging and stirring for one hour, after which 1.52grams of 2-amino benzothiazole were added and reacted for one hour. Thereaction mixture was then nitrogen stripped for one hour at 190° C.,after which the temperature was lowered to 150° C. and 272 grams ofS100NLP were added and mixed for 15 minutes, following which the reactorwas drained to give the product having a K.V. at 100° C. of 2184centistokes.

EXAMPLE 6

The 2 liter resin kettle was charged with 200 grams of the ReactionProduct of Example 1 and 200 grams of S100NLP. The temperature wasraised to 190° C. while stirring under a nitrogen sparge and maintainedfor one hour. At the end of this time, 1.1 grams of 2-aminothiazole wereadded and reacted for one hour under the nitrogen. The reaction mixturewas then nitrogen stripped for one hour at 190° C. The temperature waslowered to 150° C. and 272 grams of nitrogen sparged S100NLP were addedand mixed for 15 minutes, after which the reactor was drained to givethe product having a K.V. at 100° C. of 1810 centistokes.

EXAMPLE 7

The 2 liter resin kettle was charged with 200 grams of the Product ofExample 1 and 200 grams of S100NLP. The temperature was raised to 190°C. while stirring and nitrogen sparging. Then 1.2 grams of1-methyl-1-phenylhydrazine dissolved in 2.4 grams of S100NLP were addedover a 10-minute period and reacted for one hour while lightly spargingwith nitrogen. The reaction mixture was then nitrogen stripped for onehour at 190° C. The temperature was lowered to 150° C. and 272 grams ofS100NLP were added and mixed for 15 minutes. The 272 grams of S100NLPhad been previously nitrogen sparged for one hour before adding. Thereaction mixture was then drained to give the product having a K.V. at100° C. of 1826 centistokes.

EXAMPLE 8

The 2 liter resin kettle was charged with 500 grams of the ReactionProduct of Example 1 and 500 grams of S100NLP. The temperature wasraised to 190° C. while stirring and nitrogen sparging and held therefor one hour. The temperature was then lowered to 150° C. and 5.5 gramsof N-isopropylethylene diamine were added over a 15-minute period,following which the temperature was raised to 190° C. and the aminereacted for a one-hour period. The reaction mixture was then nitrogenstripped for one hour at 190° C., cooled to 150° C. where 680 grams ofS100NLP were added and mixed for 15 minutes. Following this, the reactorwas drained to give the product having a K.V. at 100° C. of 1438centistokes.

EXAMPLE 9

The 2 liter resin kettle was charged with 200 grams of the ReactionProduct of Example 1 and 200 grams of S100NLP. The temperature wasraised to 190° C. and held here for one hour while stirring and nitrogensparging. Then 1.08 grams of N-aminomorpholine were added slowly andreacted for one hour at 190° C. The reaction mixture was nitrogenstripped for one hour at 190° C., following which the temperature waslowered to 150° C. and 272 grams of S100NLP were added and mixed for 15minutes. The reactor was then drained to give the final product having aK.V. at 100° C. of 2376 centistokes and a nitrogen content of 0.28 wt.%.

EXAMPLE 10

1816 grams of Nordel 1320 was added to the reactor, that is the 21/2gal. masticator, and heated at 140° C. under nitrogen until bandingoccurred. Then, 20 grams of octadecyl mercaptan, 14.4 grams of N-vinylpyrrolidone and 3.6 grams of Lupersol 130 were added to the reactorfollowed by heating to 170° C. for 45 minutes, while mixing undernitrogen. The reactor was then cooled to 140° C. and 10 grams ofoctadecyl mercaptan, 14.4 grams of N-vinyl pyrrolidone and 3.6 grams ofLupersol 130 was added to the reactor while mixing and stirring undernitrogen. The masticator, that is the reactor, was heated to 170° C. for60 minutes under nitrogen while continuing mixing, following which 4540grams of S100NLP were added and mixed in for about one hour. Themasticator was drained to give the final product which was an oilsolution of an ethylene copolymer grafted with N-vinyl pyrrolidone,which would be useful as a V.I. dispersant modifying additive inlubricating oil. The final product had a kinetic viscosity at 100° C. of1080 centipoise and the grafted polymer therein had a T.E. of 1.65.

Nordel 1320 is a terpolymer of about 53 wt. %, ethylene, about 43.5 wt.% propylene and about 3.5 wt. % of 1,4-hexadiene. It has a Mooneyviscosity at 212° F. of about 25 and is sold by the DuPont Company.

EXAMPLE 11

1816 grams of the ethylene-propylene rubber used in Example 1 of 2.8T.E. were added to the 21/2 gal. masticator which was then mixed for 45minutes at 120° C. under nitrogen to form a band. Then 2 grams ofPennstop 2697, which is diethyl hydroxyamine sold as a commercial chainstopping agent, were added over a period of about five minutes. Then 30grams of N-vinyl pryrrolidone was added over a 5-minute period. This wasfollowed by the addition of 2 grams of Di-CUP-R (dicumyl peroxide),dissolved in 4 grams of polyisobutylene of 500 molecular weight over a5-minute period. The temperature of the reaction mass was then raised to160° C. and maintained for a soak period of 30 minutes. 30 grams ofN-vinyl pyrrolidone was added at the 160° C. temperature followed by 2grams of DI-CUP-R dissolved in 4 grams of the 500 molecular weightpolyisobutylene, followed by a heat soaking period, while mixing, of 60minutes at 160° C. After this, the temperature was raised to 175° C. and10 lbs. of S100NLP were added, followed by nitrogen stripping for 11/4hours. The reactor was then drained to give the final product having thefollowing characteristics:

K.V. at 100° C.=1467 centistokes

Nephelometer Haze=71 (At a reading of about 75 haze will become visibleto the naked eye.);

Nitrogen Content of 0.30 wt. % based on the grafted polymer; and a

T.E. for the grafted polymer of 2.60.

EXAMPLE 12

1816 grams of the ethylene-propylene rubber of Example 1 was added tothe 21/2 gal. masticator reactor and mixed for 45 minutes at 120° C.under nitrogen. Then 2 grams of Pennstop 2697 were added and mixed in.30 grams of N-vinyl pyrrolidone were added over a 5-minute periodfollowed by the addition of 2 grams of Di-CUP-R dissolved in 4 grams ofpolyisobutylene of 500 molecular weight (PIB 500) over a period of 5minutes. The temperature was then raised to 160° C. and maintained for asoak period of 30 minutes. Following this 1 gram of Pennstop 2697 wasadded over 5 minutes, 30 grams of N-vinyl pyrrolidone was added over 5minutes, followed by the addition of 2 grams of Di-CUP-R, in 4 grams ofPIB 500 in 5 minutes, later followed by 5 minutes of mixing. Then 2grams of Di-CUP-R in 4 grams of PIB 500 was added, followed by 5 minutesof mixing. Then 2 grams of Pennstop 2697 was added followed by mixingfor 5 minutes. Next, 30 grams of N-vinyl pyrrolidone was added followedby mixing for 5 minutes, followed by the addition of 2 grams of Di-CUP-Rdissolved in 4 grams of PIB 500 followed by 5 minutes of mixing. Thereactor contents were then heat soaked for 30 minutes at 160° C.,followed by heating to 175° C. which temperature was maintained for 30minutes. 10 lbs. of S100NLP were added, followed by nitrogen strippingfor 11/4 hours. The reactor was then drained to give a productcontaining 0.43 wt. % nitrogen, based on the weight of grafted polymer,having a kinetic viscosity at 100° C. of 969 centistokes, and containinga polymer having a T.E. of 1.36. At a 14.3 wt. % concentration of thereaction product in oil, the nephelometer haze heading was +111,indicating that visible haze was present.

COMPARISON EXAMPLES A TO E

A series of examples were carried out in which the chain stopping agentwas not used, which shows that the resulting material that formedresulted in the formation of gel and was not completely oil-soluble.

COMPARISON EXAMPLE A

Four pounds of the ethylene-propylene copolymer rubber of Example 1having a T.E. of about 2.8 were added to the masticator. The copolymerwas heated and mixed in the presence of air until its T.E. had beenreduced to 2.1. The masticator was then flushed with nitrogen and 35grams of maleic anhydride was added, while the temperature was raised to175° C. as the material was worked in the masticator. 5 grams ofLupersol 130 were dissolved in a sufficient amount of S100NLP to make 50milliliters (10% active ingredient) of the oil solution of theinitiator. 20 milliliters of this solution were added while mixing at175° C. under nitrogen. 30 minutes later another 10 milliliters of thesolution were added. Ten minutes later another 10 milliliters of theperoxide solution were added. Ten minutes later still another 10 mil. ofperoxide solution were added. This stage addition, i.e. periodicaddition was done in order to obtain good dispersancy of the peroxide inthe solid ethylene-propylene copolymer. The masticator contents weresoaked, that is mixed, under the nitrogen blanket for another 60minutes, after which 4540 g. of Solvent 100NLP were added and mixed,followed by draining the reactor to give the product.

COMPARISON EXAMPLES B TO E

These were carried out in the same manner noted above except for thechanges noted in the following Table I.

Comparison Examples A to E are summarized in the following Table I.

                                      TABLE I                                     __________________________________________________________________________    Comparative Examples                                                                           A       B       C       D         E                          __________________________________________________________________________    Ethylene-Propylene Copolymer, g.                                                               1816 g. 1816 g. 1816 g. 1816 g. 18                           Maleic Anhydride, g.                                                                           35 g.   45 g.   45 g.   45 g.   45 g.                        Peroxide Addition, ml. solution                                                                50 (10% a.i.)                                                                         90(10% a.i.)                                                                          70 (12% a.i.)                                                                         50 (2.5% a.i.)                                                                        None                         1st. addition, ml./Temp. °C.                                                            20/175° C.                                                                     30/175° C.                                                                     20/150° C.                                                                     20/140° C.                    Time interval, min.                                                                            30 min. 30 min. 30 min. 30 min.                              2nd. addition, ml./Temp. °C.                                                            10/175° C.                                                                     20/175° C.                                                                     10/150° C.                                                                     10/170° C.                    Time interval, min.                                                                            10 min. 10 min. 30 min. 30 min.                              3rd. Addition, ml./Temp. °C.                                                            10/175° C.                                                                     20/175° C.                                                                     10/150° C.                                                                     10/170° C.                    Time interval, min.                                                                            10 min. 10 min. 30 min. 30 min.                              4th. Addition, ml./Temp. °C.                                                            10/175° C.                                                                     20/175° C.                                                                     10/150° C.                                                                     10/170° C.                    Time interval, min.                                                                            --      --      30 min. 30 min.                              5th. Addition, ml./Temp. °C.                                                            --      --      10/150° C.                                                                     --                                   Time interval, min.                                                                            --      --      30 min. --                                   6th. Addition, ml./Temp. ° C.                                                           --      --      10/150° C.                                                                     --                                   Soak Temp./Time, °C./min.                                                               175° C./60 min.                                                                175° C./60 min.                                                                150° C./60 min.                                                                170° C./60                                                                     150° C./120 min.                                                       170° C./60 min.       Addition of oil, g.                                                                            4540    4540    4540    4540    none                         Product          Gelled  Gelled  Gelled  Gelled  No significant                                                                amount of maleic                                                              anhydride                    __________________________________________________________________________                                                     grafted.                 

Examples A to D of Table I show that even adding the peroxide in smallincrements, without the chain stopper did not prevent gelling. Example Dused only 1.25 g. of actual peroxide and still gelling occurred. ExampleE shows that without the peroxide no substantial amount of graftingoccurred.

EXAMPLE 13

Part A

100 lbs. of the solid ethylene-propylene copolymer rubber used inExample 1 was added to a 50 gal. rubber masticator in the form of five20 lb. pieces. The copolymer was masticated and nitrogen stripped in theDow-Therm heated masticator until the temperature reached 210° F. 1 lb.of t. dodecyl mercaptan was added through a dropping funnel over a 15minute period, followed by the addition of 2.1 lbs. of melted maleicanhydride, added through said dropping funnel. Initially, 100 ml. of themaleic anhydride was added. Then the remaining maleic anhydride wasadded over a 15 minute period simultaneously while adding 0.9 lbs. of1.2 lbs. of an initiator solution that had been made up consisting of0.2 lbs. of ditertiary butyl peroxide dissolved in a mixture consistingof 0.7 lbs. of PIB 500 and 0.3 of a lb. of ISOPAR M which is ahydrocarbon solvent. After this 15 minute period, then the remaining 0.3lbs. of said initiator solution were added over a five minute period.This last addition was followed by soaking and mixing for 50 minutes,followed by nitrogen stripping. Then 425 lbs. of S100NLP oil, which havebeen previously sparged with nitrogen to remove moisture and volatiles,were added to the masticator in a series of small increments, eachincrement being mixed into the reaction mass before the next increment.The first increment was 20 lbs. followed by increments of 25 lbs., 30lbs., 40 lbs., 50 lbs., 50 lbs., 50 lbs., 50 lbs. and then the balance.The temperature was lowered to 200° F. while mixing continued. Then themasticator was drained to give the oil solution of the ethylenecopolymer rubber grafted with maleic anhydride. The concentrate titratedto 0.192 meq. acid/g. of the grafted polymer.

Part B

A reactor was charged with 100 lbs. of S150NLP mineral lubricating oilwhich was heated to 100° C. and nitrogen stripped. Following this, 100lbs. of the oil solution of the ethylene copolymer grafted with maleicanhydride prepared in Part A were added to the reactor followed bymixing, nitrogen stripping and heating until the temperature reached190° C. Then, 0.35 lbs. of N-aminopropyl morpholine (NAPM) dissolved in1 lb. of said oil was added over a 20-minute period to the reactorthrough an inlet line which was then followed with 1/2 lb. of said oilto flush the line. Mixing and heating continued for one hour undernitrogen after which 19 lbs. of said oil were added, followed by vacuumstripping for one hour and then draining to give the final product,which was useful as a multi-functional V.I.-dispersant additiveconcentrate. This product analyzed 0.27 wt. % nitrogen based on theweight of the polymer, i.e. the aminated grafted polymer. The aminatedgrafted polymer had a T.E. of 2.46. The haze level of the concentratewas at a nephelometer reading of 102.

EXAMPLE 14

A lubricating oil composition was prepared by mixing 13 wt. %, based onthe weight of the total composition, of the final product of Part B ofExample 13; that is, the oil concentrate of the V.I. dispersantadditive, about 1.4 wt. % of a nonylphenol sulfide additive as anantioxidant, 1.3 wt. % of an overbased 400 Total Base No. magnesiumsulfonate additive, 1.8 wt. % of a zinc dialkyldithiophosphate additive(about 75 wt. % active ingredient), 0.25 wt. % of a pour depressantadditive, and about 82.25 wt. % of a mineral lubricating oil, to form a10W40 crankcase oil having a viscosity of about 14.5 centistokes at 100°C. This oil was tested in the MS-VD test and passed, having a sludgerating of 9.63; a varnish rating of 7.04; a piston skirt varnish ratingof 6.77; a cam and lifter wear average of 0.0050 inch and a maximum camwear of 0.008 inch.

EXAMPLE 15

A 10W40 lubricating oil composition was prepared showing the material ofthe invention supplemented by other dispersants, by mixing about 12 wt.%, based on the total composition, of the final product of Part B ofExample 13, 1.1 wt. % of antioxidant, 2.2% of an overbased metalsulfonate, 1.45 wt. % of a zinc dithiophosphate additive, and otherdispersant/detergents along with antifoam, antifriction, and pourdepressant additives, with 74.5 wt. % of lubricating oil.

What is claimed is:
 1. A process comprising grafting in the substantialabsence of solvent a hydrocarbon polymer of C₂ to C₂₈ olefin, saidpolymer having a number average molecular weight in the range of about5,000 to 500,000 with an unsaturated material selected from the groupconsisting of: (A) ethylenically unsaturated C₃ to C₁₀ carboxylic acidhaving 1 to 2 carboxylic acid groups or an anhydride group, and (B)nitrogen-containing ethylenically unsaturated monomers containing 6 to30 carbon atoms and 1 to 4 nitrogen atoms, in the presence of a freeradical initiator and a chain stopping agent comprising at least onemember selected from the group consisting of aliphatic mercaptans having4 to 24 carbon atoms, diethyl hydroxyl amine, cumene and phenols, saidgrafting being conducted in a manner and under conditions sufficient toform a substantially oil soluble graft copolymer useful as a viscosityindex improver-dispersant additive for lubricating oil compositions. 2.A process according to claim 1, wherein said hydrocarbon polymer is ahydrogenated copolymer of styrene with at least one aliphatic dieneselected from the group consisting of butadiene and isoprene.
 3. Aprocess according to claim 2, wherein said hydrocarbon polymer is ahydrogenated polymer of blocks of styrene with blocks of said diene. 4.A process according to claim 1, wherein said hydrocarbon polymer is acopolymer of ethylene with a C₃ to C₂₈ alpha olefin.
 5. A processaccording to claim 4, wherein said hydrocarbon polymer consistsessentially of ethylene and propylene.
 6. A process comprising graftingin the substantial absence of solvent an oil-soluble ethylene copolymercomprising about 15 to 90 weight % ethylene and about 10 to 85 weight %of C₃ to C₂₈ alpha-olefin, said copolymer having a number averagemolecular weight within the range of about 5,000 to 500,000 with anunsaturated material selected from the group consisting of: (A)ethylenically unsaturated C₃ to C₁₀ carboxylic acid having 1 to 2carboxylic acid groups or an anhydride group, and (B)nitrogen-containing ethylenically unsaturated monomers containing 6 to30 carbon atoms and 1 to 4 nitrogen atoms, in the presence of a freeradical initiator and a chain stopping agent comprising at least onemember selected from the group consisting of aliphatic mercaptans having4 to 24 carbon atoms, diethyl hydroxyl amine, cumene and phenols, saidgrafting being conducted in a manner and under conditions sufficient toform a substantially oil soluble graft copolymer useful as a viscosityindex improver-dispersant additive for lubricating oil compositions. 7.A process according to claim 6, wherein said copolymer is grafted withsaid unsaturated material by mixing said copolymer, unsaturatedmaterial, free radical initiator and chain stopper at about 120° to 250°C. for about 0.005 to 12 hours.
 8. A process according to claim 6,wherein the grafted material is subsequently mixed with minerallubricating oil to form an oil concentrate or an oil composition.
 9. Aprocess according to claim 6, wherein said mixture comprises about 0.1to 10 wt. % of said unsaturated material, about 0.05 to 10 wt. % of saidchain stopping material and about 0.005 to 1 wt % of said free radicalinitiator, all of said weight percents being based upon the weight ofsaid copolymer.
 10. A process according to claim 6, wherein ahomogeneous mixture is formed of said ethylene copolymer, unsaturatedmaterial, initiator and chain stopping agent by heating and mixing at afirst temperature below the temperature at which said initiatorgenerates substantial free radicals, and then heating and mixing at asecond higher temperature at which said initiator generates substantialfree radicals and a major proportion of said grafting takes place.
 11. Aprocess according to claim 10, wherein said first temperature is in therange of about 100° to 160° C. and said second temperature is in therange of about 170° to 240° C.
 12. A process according to claim 10,wherein said process is carried out in multiple stages, said first stagecomprising forming said homogeneous mixture at said first temperature,then heating and mixing at said second temperature to effect grafting;and at least one additional stage of cooling to said first temperature,adding additional unsaturated material, initiator, and chain stoppingagent at said first temperature and reheating and mixing to said secondtemperature to effect grafting of said additional unsaturated material.13. A process according to claim 6, wherein said ethylene copolymer is anormally solid rubber at room temperature and mixing is carried out in amechanical mixer which heats and kneads said rubber, unsaturatedmaterial, initiator and chain stopping agent into a homogeneous solidrubbery mass in which grafting takes place in the solid state.
 14. Aprocess according to claim 6, wherein said unsaturated material is saidunsaturated carboxylic acid or anhydride.
 15. A process according toclaim 14, wherein said unsaturated material is maleic anhydride.
 16. Aprocess according to claim 14, wherein said graft material is dissolvedin a mineral lubricating oil and reacted with an amine having 2 to 60carbon atoms and 1 to 12 amine groups to form an oil solubleViscosity-Index improving--dispersant additive concentrate.
 17. Aprocess according to claim 16, wherein said carboxylic acid material ismaleic anhydride and said amine is a polyamine having at least oneprimary amine group.
 18. A process according to claim 6, wherein saidcopolymer consists essentially of about 30 to 80 weight % ethylene andabout 20 to 70 weight % propylene, and has a number average molecularweight in the range of about 10,000 to 200,000.
 19. A process accordingto claim 6, wherein said free radical initiator is a peroxide.
 20. Aprocess according to claim 19, wherein said chain stopping agent is a C₄to C₂₄ aliphatic mercaptan.
 21. A process according to claim 6, whereinsaid unsaturated material is said nitrogen-containing ethylenicallyunsaturated monomer.
 22. A process according to claim 21, wherein saidnitrogen containing monomer is selected from the group consisting ofvinyl pyridenes, vinyl pyrrolidones, acrylates and methacrylates.
 23. Aprocess according to claim 6, wherein said ethylene copolymer consistsof ethylene and propylene.
 24. A process according to claim 6, whereinsaid ethylene copolymer is a terpolymer of ethylene, propylene and anunsaturated diene.
 25. The product produced by a process according toclaim
 1. 26. The product produced by a process according to claim
 2. 27.The product produced by the process according to claim
 4. 28. Theproduct produced by the process according to claim
 6. 29. The productproduced by the process according to claim
 8. 30. The product producedby the process according to claim
 16. 31. The product produced by theprocess according to claim
 21. 32. A lubricating oil compositioncomprising a lubricating oil and the product of claim
 25. 33. Alubricating oil composition comprising a lubricating oil and the productof claim
 26. 34. A lubricating oil composition comprising a lubricatingoil and the product of claim
 27. 35. A lubricating oil compositioncomprising a lubricating oil and the product of claim
 28. 36. Alubricating oil composition comprising a lubricating oil and the productof claim
 29. 37. A lubricating oil composition comprising a lubricatingoil and the product of claim
 30. 38. A lubricating oil compositioncomprising a lubricating oil and the product of claim
 31. 39. A processcomprising grafting in the substantial absence of solvent at atemperature from about 120° to 250° C. for about 0.005 to 12 hours, ahydrocarbon polymer of C₂ to C₂₈ olefin, said polymer having a numberaverage molecular weight in the range of about 5,000 to 500,000 withfrom about 0.1 to 10 weight % of an unsaturated material selected fromthe group consisting of: (A) ethylenically unsaturated C₃ to C₁₀carboxylic acid having 1 to 2 carboxylic acid groups or an anhydridegroup, and (B) nitrogen-containing ethylenically unsaturated monomerscontaining 6 to 30 carbon atoms and 1 to 4 nitrogen atoms, in thepresence of about 0.005 to 1.0 weight % of a free radical initiator andabout 0.05 to 10 weight % of a chain stopping agent consisting of one ormore of an aliphatic mercaptan having 4 to 24 carbon atoms, diethylhydroxyl amine, cumene or phenols, all of said weight percentages beingbased upon the weight of said copolymer.
 40. A process according toclaim 39, wherein said hydrocarbon polymer is an oil-soluble ethylenecopolymer comprising about 15 to 90 weight % ethylene, about 10 to 85weight % of one or more C₃ to C₂₈ alpha-olefins, and from 0 to about 20weight % of one or more non-conjugated diolefins.
 41. A processaccording to claim 40, wherein said hydrocarbon polymer is ahydrogenated copolymer of styrene with at least one aliphatic dieneselected from the group consisting of butadiene and isoprene.
 42. Aprocess according to claim 40, wherein said hydrocarbon polymer is acopolymer of ethylene with C₃ to C₂₈ alpha olefin.
 43. A processaccording to claim 40, wherein said copolymer is grafted with saidunsaturated material by mixing said copolymer, unsaturated material,free radical initiator and chain stopper at about 120° to 250° C. forabout 0.005 to 12 hours.
 44. A process according to claim 40, wherein ahomogeneous mixture is formed of said ethylene copolymer, unsaturatedmaterial, initiator and chain stopping agent by heating and mixing at afirst temperature below the temperature at which said initiatorgenerates substantial free radicals, and then heating and mixing at asecond higher temperature at which said initiator generates substantialfree radicals and a major proportion of said grafting takes place.
 45. Aprocess according to claim 40, wherein said ethylene copolymer is anormally solid rubber at room temperature and mixing is carried out in amechanical mixer which heats and kneads said rubber, unsaturatedmaterial, initiator and chain stopping agent into a homogeneous solidrubbery mass in which grafting takes place in the solid state.
 46. Aprocess according to claim 40, wherein said unsaturated material is saidunsaturated carboxylic acid or anhydride.
 47. A process according toclaim 40, wherein said copolymer consists essentially of about 30 to 80weight % ethylene and about 20 to 70 weight % propylene, and has anumber average molecular weight in the range of about 10,000 to 200,000.48. A process according to claim 40, wherein said free radical initiatoris a peroxide.
 49. A process according to claim 40, wherein saidunsaturated material is said nitrogen-containing ethylenicallyunsaturated monomer.
 50. A process according to claim 40, wherein saidethylene copolymer consists of ethylene and propylene.
 51. A processaccording to claim 40, wherein said ethylene copolymer is a terpolymerof ethylene, propylene and an unsaturated diene.
 52. A process accordingto claim 40, wherein the grafted material is subsequently mixed withmineral lubricating oil to form an oil concentrate.